The Request Rate makes me confused

[bringyou]

Hello, I' am using Kibana's stack monitoring tools, and I found something confusing me, that is, in the indices overview window, there is a line chart called "search rate"

and in advance window, there is a line chart called "request rate"

(The index shown here has 3 primary shards, 6 replica shards, no routing)
We can see, those two charts has the same data, but different descriptions, which makes me confused.
What does the "search total" in the request rate chart mean?
Or what does the description "per shard" mean ?
In my poor opinion, "search total" in the request rate chart should equal client side search rate,
and data in search rate chart should equals client side search rate multiplies primary shards count. But, it doesn't, actually, they seem to be all the same, so why they have different descriptions?

[DeeeFOX]

@bringyou

what does the description "per shard" mean

To my understanding:

search_total =
search_per_shards * how_many_shards_excute_the_search

AND

request_total =
( index_per_primary_shards * how_many_primary_shards_excute_the_index )
+
( search_per_shards * how_many_shards_excute_the_search )

[bringyou]

Thanks for your reply. So the "search total" in "request rate" chart and the search rate chart are the same thing. But still wonder why they have different description